Saw



i Patented JulyilZ, 1927.

UNITED STATES igasass PATENT'OFFICE.

lI'OHN C. DE PENNING, 0F PORTLAND, OREGON, ASSIGNOR T0 CENTRAL DOOR AND LUM.'-

. BEE COMPANY, OF PORTLAND, OREGON, A CORPORATION.

SAW.

Application mea July 19,

' `My invention relates to Wood-cutting saw and 4has, for its particular object the provision of a patchin saw adapted to form a kerf wedge-shape in cross-Section and cigarshaped in plan so as to form the incisions required to carr out my improved patching method descri ed in a, co-pending application for patent entitled Method of patching, filed July 19, 1926, Serial No.

I attain this object in a circular wood-cutting saw of the character described' provided with two sets of cutting teeth, each extending f a substantial distance up opposite sides of the saw upon lines receding from radii of said sawand diverging at equal opposite angles. The teeth in said oppositely disposed sets register with each other and wardly from said points, lyin meet at the periphery to form sharp points, the cutting edges of said teeth extending inwholly within'divergent planes, thereby a apted to form a kerf Wedge-shaped in cross-Section and cigar-shaped in plan.

The details of my improved saw are hereinafter described in greater detail with reference to thev accompanying drawings, in which:

Fig. 1 is an elevation of said saw; and

Fig. 2 an enlarged fragmentary section through the latter, shown super-imposed over a kerf formed thereby.

My improved saw aA preferably is formed with parallel sides a and has two sets of teeth a2 formed about its periphery. Said sets of-teeth are formed one upon each of said sides and diver e angularly from 'the periphery at substantially 4equal opposite angles. The separate teeth in eachof said sets are in registration with the similar teeth in the set 4in the opposite side and thus form i sharp spaced points as about periphery. The

teeth in registration are each provided with cutting edges a4 extending inwardly from said points up each side of the saw and said cutting edges a* extend` wholly within di; vergentplanes so as to form a kerf b which is wedge-shaped in cross section.

As is noted in my co-pending application a saw used in patching is mounted upon a mandrel, which may be moved relatively toward and from the board to be patched and thus when my improved saw a is lowered i into such board and not moved longitudinally thereto, a kerf b is formed which is cigar- 1928. Serial No. 123,571.

shaped in. section and the base portion b thereof is a continuous curve.

In practice a patching saw of the character .described is rovided with teeth extending inwardly substantially a fifth 0f its diameter and about five times its thickness so as to permit a substantial variance in the depth and width of the kerf to be formed for the reason that pitch pockets and other imperfections to be removed by such kerf vary considerably in 4width `and depth. That is, an imperfection to be removed is cut away merely by loweringsaidsaw into the board and. sometimes in drawing said board and.

said saw longitudinally relatively to each other. The deeper al saw kerf is formed by said saw the greater its Width and thus to permit'the removal of deep and wide pitch pockets it is necessar that such teeth a be of considerable lengt and divergence to be capable of removing large pitchV pockets.

One size patching saw, for example, is approximatel five and one-half inches in diameter an the teeth extend inwardl from its periphery about one inch, the b ade of the saw being approximately one-fourth of an inch thick.

It is to be noted that the saw teeth are arranged so thatl if the saw is rotated in one direction (counterclockwise as viewed lin Fig. 1) the points a3 will be in advance of the remainder of the cutting edges a. The lead or angle given such teeth is such that if lines were extended along the cutting edges of such teeth, suchv lines would all be substantially tangential to a, circle of one-half the diameter of the saw. In the saw shown in Fig. 1, such circle would be located approximately one-third of the way between the roots ofsuch saw teeth and the eye thereof. Without this lea-d or angle the saw would be ineffective to clear out the chips from the kerf. That is, the cutting edge or point of the ordinary saw is swaged so as to cut a wider kerf than the thickness of the root of the tooth and the blade thereof, to provide clearance therefor. This, of course, is not possible in my improvedsaw because the, teeth necessarily terminate in.

I claim:

1. A circular wood-cutting saw of `the character described havin peripheral teeth, the cutting edges of whic extend inwardly of the saw a distance substantially greater than the thickness of such saw, the cutting edges of each tooth being in registration with those of the remainder, meeting at the periphery to form a sharp point, such saw teeth thus being arranged to form a kerf of uniform, wedge-shaped cross-section.

2. A circular wood-cutting saw of the character described having teeth, thecutting ed es of which extend inwardly of the saw a istance in excess of one-third of the radius of such saw, the cutting edges of each tooth being in registration with those of the remainder, meeting at the peirphery to form a sharp point, such saw teeth thus being arranged to form a kerf of uniform, wedgeshaped cross-section.

3. A circular wood-cutting saw 'of the' being arranged to form a'kerfggi uniform,4

wedge-shaped 'cross-section, such cutting edges being inclined towards their points along lines substantially tangentialy y.to a circle approximately one-half the diameter of the saw.

JoHN'o. DE PENNING. 

